Adjustable presser foot for blind stitch sewing machines



F. GRECO March 6, 1956 ADJUSTABLE PRESSER FOOT FOR BLIND STITCH SEWING MACHINES 3 Sheets-Sheet 1 Filed Aug. 12, 1953 IN V EN TOR. FQANK Gpsco F. GRECO March 6, 1956 ADJUSTABLE PRESSER FOOT FOR BLIND STITCH SEWING MACHINES 3 Sheets-Sheet 2 Filed Aug. 12, 1953 INVENTOR. FRANK 696cc) BY 3 Sheets-Sheet 3 INVENTOR. PA/YK Uveco F. GRECO March 6, 1956 ADJUSTABLE PRESSER FOOT' FOR BLIND STITCH SEWING MACHINES Filed Aug. 12, 1953 ADJUSTABEE PRESSERFOOT FOR BLIND STITCH SEWING MACHINES Frank Greco, Hasbrouck Heights, J.

Application August 12, 1953, Serial No. 373,866

'3 Claims. (Cl. 112-235) This invention relates to an adjustable presser foot for sewing machines which is a great improvement over those presently in existence. The invention has particular application to the blind stitch type of machine which uses a curved needle and which is described'in the United States patents to Dearborn, Numbers 1,964,381 and 2,064,153.

While this invention relates only to a particular part of the sewing machine, i. e. the presser foot or work plate, a short discussion of the operation of such a machine appears to be in order.

The blind stitch type of machine is adapted to form a number of small penetrating stitches of extremely small width on the visible or right side of the work. The Work may be cloth or any other material capable of being sewn.

The principal disposition of the sewing thread is on the underside or wrong side of the work so that the sewing stitches in the finished product are practically invisible.

The blind stitch machine is provided with a pressenfoot which bears a longitudinal recess therein. A curved needle bearing a thread supply atits forward end .is adapted to move reciprocatingly in a transverse direction across the longitudinal recess. A looping mechanism is provided to form the forward end of the thread into a loop :so that the needle will insert a portion of the thread into the previously formed loop upon its succeeding forward movement. The loop is then drawn tight and the stitch locked in place.

The presser vfoot in the conventional blind stitch sewing machine is also preferably provided withan upwardly extending thread guiding post so that the thread :may be properly guided after the work has left the machine and the stitching upon the -work has been completed. A ridge forming member is also provided to :move the'work into and out of the :recess in the presser foot. Feeding means are employed to move the work transversely and rearwardly with respect to the presser foot.

The operation of .the conventional machine will 'be explained commencing with that position of the machine wherein the needle is in its most forward position. At this point the looper engages the forward end of the thread supply of the needle and forms a loop. The needle is then moved back and the looper brings the loop in line with the needle so that the needle will pass through the loop upon its next forward movement. The ridge forming member then pushes the work into the recess in the work plate so that the needle passes through the Work and thence through the loop previously formed in the thread. Since, however, the needle can go through only the portion of the work that has been pushed into the recess in .the presser foot the portion of the stitch showing upon the underside or right side of the work is extremely small.

After the needle has passed through the work and the thread loop it is withdrawn from its forward position.

nitcd States Patent The looper then pulls the thread tight so that'the tstitch ice is locked in place. The looper then forms another loop for the next stitch.

While the .looper is tightening the previously formed stitch the ridge forming member is moved downwardly so that the work falls below the upper face of the presser foot. The movement of the work is facilitated by the optional provision of a work engaging member which springingly bears against the portion of the work disposed within the recess in the presser foot. After the ridge forming member is moved downwardly the work is fed rearwardly and transversely with respect to the presser foot and placed in position for the formation of the next stitch. Where a skip stitch is to be produced the ridge forming member does not push the work into the recess in the presser foot when the succeeding skip stitches are formed so that the skip stitches merely lie loosely upon the wrong side of the work until it is desired to form the next penetrating stitch when the ridge forming member again pushes a portion of the work into the recess in the presser foot. If, however, it is desired to have every stitch penetrate the work the ridge forming member, after the first stitch is formed, again pushes a portion of the work into the recess in the presser foot and the cycle is repeated.

The conventional presser foot used in the blind stitch sewing machine is-satisfactory so long as only one thickness of material is to be worked upon. However, the presser foot is not satisfactory where different thicknesses of material are to be worked upon. From the foregoing discussion it can be easily seen that the recess or opening in the presser 'foot through which the material or work is forced during the formation of the penetrating stitches must be larger or smaller depending upon the thickness of the work. Thicker work requires a wider opening in the presser foot and thinner work a narrower. If too wide an opening is formed in the presser foot the work will be pushed up too high by the ridge forming member and the width of the penetrating stitch on the right side of the work will 'be too great. 0n the other hand, if too narrow an opening is used the penetrating stitches will not penetrate the work. Furthermore the machine may jam.

It has therefore hitherto been the practice to supply the sewing machine with a number of presser feet provided with openings of different sizes. However presser feet must be made to close tolerances and are rather expensive. The provision, therefore, of a number of presser feet has never been satisfactory.

it is an object of this invention to provide a presser foot for a sewing machine in which the size of the opening into which the work is pushed by the ridge forming member during the formation of penetrating stitches is adjustable to compensate for the thickness of the work sewn by the machine.

It is a further object of this invention to provide simple replacement for the portion of the pressor foot which guides the needle so that the wearing out of this portion of the presser foot will. not require replacement of the entire foot.

Briefly stated the invention comprises an adjustable presser foot for a sewing machine which is formed with a base member provided with the conventional longitudinal opening therein to receive the work during the formation of the penetrating stitches and which is also provided with an additional opening which is in communication with the first-named opening. The additional opening does not necessarily extend "completely through the thickness of the base member. An adjustable member is disposed within the second-named opening and is reciprocatingl'y movable therein. Means are provided for rigidly holding the presser foot to the sewing machine and further means are provided for rigidly "positioning the adjustable member at fixed points within the said opening and holding same in rigid position. The adjustable member is preferably provided with a thread guiding post and also with a needle guide channel. Also preferably, but not essentially, a work engaging member is also provided.

The invention will be further described by reference to the accompanying drawings which are made a part of this specification.

Fig. 1 is a side view of a Dearborn type of blind stitch sewing machine showing the new presser foot in operating relationship thereto.

Fig. 2 is a sectional view of the presser foot and associated parts showing the position of the work in the opening in the presser foot when a penetrating stitch is to be produced.

Fig. 3 is a sectional view similar to Fig. 2 showing the position of the work after the penetrating stitch has been produced.

Fig. 4 is a perspective view of one form of the presser foot of this invention, with a portion broken away.

Fig. 5 is a sectional view of the presser foot of this invention shown in Fig. 4 taken along line 5-5 of Fig. 4.

Fig. 6 is a sectional view of the presser foot of this invention shown in Fig. 4 taken along line 66 of Fig. 4.

Fig. 7 is a perspective view of an alternative form of the presser foot of this invention with a portion thereof broken away to show the internal construction.

Fig. 8 is a sectional view of the presser foot shown in Fig. 7 taken along line 88 of Fig. 7.

Fig. 9 is a sectional View of the form of presser foot shown in Fig. 7 taken along line fi-9 of Fig. 8.

Fig. 10 is a sectional view of the form of presser foot shown in Fig. 7 taken along line 1tl1l of Fig. 8.

Referring now to the principal form of this invention as shown in Figs. 46 presser foot 11 is formed with base member 12. Base member 12 is formed with an upper face 13 and a lower face 14. Upper face 13 of base member 12 is arcuate in form. Base member 12 is also provided with a longitudinal opening 15 and a tranverse opening 15 which is in communication with longitudinal opening 15. Adjustable member 17 is disposed within transverse opening 16. Adjustable member 17 is preferably arcuate in form and is also preferably provided with needle guide channel 18 and upwardly extending thread guiding post 19 upon its upper face 20. Base member 12 bears vertical member 21 which is secured to base member 12 at 22 and 23. Arm 24 is secured to adjustable member 17 at 25 and is also formed with a plurality of arcuate recesses 26, 27, and 253. Pins 29 are secured to vertical member 21 and are disposed within recesses 26 and 28. Screw 30 is threadedly secured to vertical member 21 and bears a knurled knob 31.

Vertical members 21 bears fastening portions 32 and base member 12 bears fastening portions 33 so that the presser foot may be rigidly fastened to the sewing machine. Fastening portions 32 and 33 are adapted to hold fastening members (not shown) so that the part may be held to the machine.

Base member 12 is also preferably formed with an upwardly extending toe portion 34 and is also preferably provided with additional needle guide channels 35 and 36. Needle guide channels 35 and 36 communicate with transverse opening 16 and longitudinal opening 15 and are in line with each other. Needle guide channels 35 and 36 are also in line with needle guide channel 18 which is provided within adjustable member 17.

Needle plate 37 is also preferably provided upon base member 12 and is secured to base member 12 by screw 38. This plate may be removed after it has been worn ecause of the motion of the needle of the sewing machine across it.

Base member 12 also preferably is formed with an additional opening 39. Operating member 40 of work engaging member 41 is held within opening 39 at 42 and 43. Spring 44 is secured to base member 12 and to operating member 40 at 45 and 46 and serves to hold operating member 40 in a downward position at all times. The forward portion 47 of operating member 40 is disposed withing longitudinal recess 15. Work guide member 48 is formed with a downwardly depending portion 49 which is also disposed within longitudinal recess 15. Work guide member 48 is secured to operating member it by screw 49.

Referring now to the alternative form of this invention shown in Figs. 7-10 presser foot 51 is formed with base member 54. Base member 54 is formed with upper face 55 and lower face 56. Base member 54 is formed with longitudinal recess or opening 53 and transverse recess or opening 57. Openings 53 and 57 are in communication with each other. Adjustable member 58 is disposed within opening 57. Base member 54 also bears vertical member 59 which is secured to base member 54 at 68 and 61. Base member 54 is also formed with side portion 62 which is formed with groove 63 therein. Adjustable member 58 overlies groove 63. Screw 64 is operated by knob 65 and is adapted to rigidly position adjustable member 58 within opening 53.

Base member 54 is preferably provided with needle guide channel 66 which is in line with needle guide channel 67 preferably provided in adjustable member 58. Needle plate 68 is also preferably provided upon base member 54 and is secured thereto by screw 6%.

Thread guiding post 70 is also preferably provided upon adjustable member 58.

Work engaging member 71 is secured within opening 53 in base member 54 by means of an extension of opening 53. Work engaging member 71 is secured to base member 54 at 72 and 73. Spring 74 is secured to base member 54 and work engaging member 71 at 75 and 76 and is adapted to hold work engaging member downwardly at all times. -Work guide 77 is secured to base member 52 by screw 78.

The operation of this invention may now be explained by referring to the principal form of this invention. It is obvious that the alternative form could also be employed similarly.

Presser foot 11 is secured to the sewing machine by the use of fastening portions 32 and 33. Knob 31 is turned so as to loosen screw 30, thereby permitting adjustable member 17 to be moved within opening 16. Adjustable member 17 is then placed in the desired position depending upon the work thickness to be sewn upon. This portion can be determined either by experiment or by the use of gauge markers (not shown). After the correct position of adjustable member 17 has been set knob 31 is tightened so that adjustable member 17 is held in rigid position.

The work 80 is then positioned beneath presser foot 11 and operating member 40 of work engaging member 41. The machine is then started so that ridge forming member 81 moves upwardly into opening 15 in base member 12 of presser foot 11 and thereby forces a ridge of the work into opening 15. The pressure of ridge forming member 81 is greater than the pressure produced by spring 44 of work engaging member 41. Looper 82. has previously formed the forward end of thread 83 into a loop.

Needle 84, which is curved, then goes through the work and makes a deep penetrating stitch going through the thread loop previously made by looper $2. Needle 34 is then withdrawn from the work and looper 82 pulls the stitch tight. Ridge forming member 81 then moves downwardly and work engaging member 41 pushes the work out of opening 15 in presser foot 11. If it is now desired to produce a number of idle stitches i. e. those that do not penetrate the work the stitch cycle is repeated but the ridge forming member 81 remains in its downward position so that the work is not forced into opening 15. When it is again desired to form a work penetrating stitch ridge forming member 81 is again moved upwardly and the cycle is repeated.

Thread guiding post 19 is provided to guide the position of the thread after the sewing upon the work has been completed so that the thread will still form locked stitches.

The foregoing specific embodiments of this invention as set forth in the specification and drawings herein are for illustrative purposes and for purposes of example only. Various changes and modifications may obviously be made within the spirit and scope of this invention and would occur to those skilled in this art.

I claim:

1. An adjustable presser foot for a blind stitch sewing machine using a laterally movable needle comprising a base member formed with a substantially arcuate upper face and provided with a transverse and a longitudinal opening in communication with each other, a substan tially vertical member secured to said base member, fas' tening means upon said base member and said vertical member adapted to rigidly secure said base member to the sewing machine, an adjustable member formed with an arcuate upper face provided with a needle channel thereon disposed within said transverse opening and reciprocatingly movable therein, an arm member secured to said adjustable member and slidably secured to said vertical member, and means for removably fastening said arm member to said vertical member thereby rigidly positioning and holding said adjustable member at fixed points within said transverse opening so that the opening within said presser foot becomes of correct size to accommodate the thickness of the fabric sewn by the machine.

2. An adjustable presser foot for a blind stitch sewing machine using a laterally movable needle comprising a base member formed with a substantially arcuate upper face and provided with a transverse and a longitudinal opening in communication with each other, a substantially vertical member secured to said base member, fastening means upon said base member and said vertical member adapted to rigidly secure said base member to the sewing machine, an adjustable member formed with an arcuate upper face provided with a needle channel thereon disposed within said transverse opening and reciprocatingly movable therein, an upwardly extending thread guiding post secured to the upper face of said adjustable member, an arm member secured to said adjustable member and slidably secured to said vertical member, and means for removably fastening said arm member to said vertical member thereby rigidly positioning and holding said adjustable member at fixed points within said transverse opening so that the opening within said presser foot becomes of correct size to accommodate the thickness of the fabric sewn by the machine.

3. An adjustable presser foot for a blind stitch sewing machine using a curved laterally movable needle comprising a base member formed with a substantially arcuate upper face and an upwardly extending toe portion, said base member being also provided with a transverse and a longitudinal opening in communication with each other, an additional opening within said base member, a transverse needle channel communicating with said transverse opening, an additional transverse needle channel communicating with said longitudinal opening, said needle channels being in line with and spaced from each other, a substantially vertical member secured to said base member, fastening means upon said base member and said vertical member adapted to secure said member to the sewing machine, an adjustable member formed with an arcuate upper face provided with an additional needle channel thereon disposed within said transverse opening and reciprocatingly movable therein, said last-named needle channel being in line with and between said firstnamed needle channels, a thread guiding post upwardly disposed upon said adjustable member, a work engaging member secured to said base member, an arm member secured to said adjustable member and slidably secured to said vertical member, and means for removably securing said arm member to said vertical member thereby rigidly positioning and holding said adjustable member at fixed points within said transverse opening so that the opening within said presser foot becomes of correct size to accommodate the thickness of the fabric sewn by the machine.

References Cited in the file of this patent UNITED STATES PATENTS 683,900 Blanchard Oct. 8, 1901 1,031,767 Zabel July 9, 1912 1,739,081 Mueller Dec. 10, 1929 1,988,563 Mueller Jan. 22, 1935 

